To receive the STC, Boeing’s team completed a series of lab, ground and flight tests, including validating the KC-46’s boom and drogue aerial refuelling systems to meet FAA criteria.

The STC is one of the two required FAA airworthiness certifications. Boeing received an Amended Type Certificate for its core 767-2C aircraft configuration in December 2017, and the company expects to receive a Military Type Certificate from the US Air Force in the coming months.

When in service, the KC-46A will refuel US, allied and coalition military aircraft using its boom and hose and drogue systems. The boom allows the tanker to transfer up to 1,200 gallons of fuel per minute, while the hose and drogue systems, located on both the plane’s wing and centreline, enables the KC-46 to refuel smaller aircraft with up to 400 gallons of fuel per minute.